Bi-pin fluorescent lampholder with new insertion means



Feb. 28, 1961 J. M. PISTEY 2,973,500

BI-PIN FLUORESCENT LAMPHOLDER WITH NEW INSERTION MEANS Filed Oct. 2, 195

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Inventor'- John. M. Pisieg 5 73M 8 His A'rrovngy United States Patent f BI-PIN FLUORESCENT LAMPHOLDER'WITH NEW INSERTION MEANS Filed Oct. 2,.1958,.Ser.,N0. 764,907

'4 Claims. (Cl. 339-53) The-present invention relates-.1150 fluorescent lampholders and especially bi-pin fluorescent lampholderswhere the lamp pins are inserted by twisting the lamp about: its (longitudinal axis.

It: will be understood that most fluorescent lamps that are supported from the ceiling are removed from the lampholders from below. conventionally, these lampholders open downwardly. In buildings where there is an excessive amount of vibration due to loud noises,, heavy machines. or vehicles, serious personal injury has been known to occur. Since the lampholders are open downwardly, it oftentimes happens that the lamp pins become disengaged from the lampholder contacts and the lamp may fall onto the floor with a resounding explosion asthe glass tube is smashed tosmithereens.

The principal object of this invention is to provide a biepin fiuorescentlampholder with a novel insertion means that will hold one pin in a semi-locked position in the event the other pin is released from the lampholder.

A further object of this inventionis to provide a bi-pin fluorescent larnpholder wherein one pin must be moved into a semi-locked position before the other pin may be shifted into or out of a lamp supporting position.

' A. still further object ofthis invention is to provide a bi-pin fluorescent lampholder with a more positive locking action for the lamp pins.

The preferred embodiment of the present invention incorporates an entrance slot inthe top and front walls of the lampholder housing. Communicating with this slot is a pair of arcuate grooves in the front face of the housing which face inwardly toward each other and are adapted to receive the pins of the lamp. A complementary spring contact member is exposed within each groove to function as both a mechanical and electrical connection with the lamp pins. The innermost ends of the grooves converge toward each other slightly and it is necessary that one pin be shifted into the extreme end of itsgroove before the other pinmay be brought infrom the entrance slot to enter the other groove. This provides a morepositive locking action for the lamp pins and'tends to prevent overtravel. The contact members each have a V-shaped formation or pin seat adjacent the point of widest spacing between the grooves for supporting the pins in the normal locking position.

Once the pins are in the grooves, it should be understood that neither one of the pins may be moved out into the entrance slot unless the opposite pin is driven first out of its locked position and into the innermost end of its groove, .which may be termed a semi-locked position'. Accordingly, if one spring contact member were to lose its resilience and release one of the lamp pins, that pin would move only slightly until it engaged the outer edge of the groove near where the groove merges with 2,973,500 MeF Febs 9 1..

entrance slot but the lamp is still. supported by the oppo site. pin which is. in a semi-locked position.

the entrance slot. Here the pins would be confined until.

end of its groove. Then thefirst pin could move into the My invention-.willibe better understood from the fole lowing de'scriptiontaken in connection with the accornpanying drawing, and its scope will be pointed out in the appended claims.

Figure l is a front. elevational: view of a bi-pin lampholder embodying the present invention showing diagram! matically the twov lamp pins in a normal locked position.

Figure 2 is. a right sideelevational, view of the lamp holder of Figure 1.

Figure 3 is; an isometric Figure l.

Figures.,4-.-6-areseveral partial .views of the lampholder showing'the. principle of thisinvention as the lamp pins are. turned; through the various. positions during insertion qf'thelamp.

Figure 4. shows the lower pin in alocked position while the, other pin is confined'in. the entrance slot which prevents the lamp fromrturning.

Figure 5. is. a view similar to that of Figure 4 after the lower pinis shiftedtothe innermost end of its groove so that a twisting force may be put on the lamp to move. the upper pin into, a locked position.

Figure 6 is. a later view showing the lower pin in a semi-locked position which follows from the situation shown in Figure 5 when the lamp is. freed from manual pressure.

Figure 7 is a partial end viewof a standard bi-pin fluorescent lamp showing the. spacing of: the lamp pins.

Referring in detail to the drawing, and especially to Figures 1 and 3, the lampholder is shown with a hollow housing formed by a recessed base member 10 and a front cover plate 11. A metal angle bracket 12 is pictured at the lower portion of the lampholder to provide means for mounting the lampholder on a supporting surface. The upright portion of the bracket 12 has. a small opening for receiving an eyelet. 13 which extends. completelythrough the lampholder and is fastened therein. Thiseyelet not only fastens the bracket 12 but it holds the cover plate 11 over the front of the base. Lead wires 14 extend out through the bottom of the lampholder and are soldered or otherwise fastened, within the housing to the similar spring contact members 15.

The drawing shows the mounting bracket 12 at the lower portion of the lampholder but it will be understood that when this lampholder is assembled in a lighting fixture and the fixture is hung from the ceiling, the lampholder will be turned upside-down from the position shown in the present drawing. For purposes of this application, the wall 16 of the housing which is remote from the mounting bracket 12 will be referred to as the top wall. An entrance slot 17 is formed in both the top wall and front wall of the housing for receiving the two pins of a bi-pin fluorescent lamp. Figure 7 has been included in the drawing to show a portion of one end of a fluorescent lamp 18 with its lamp base 19 of insulating material and pair of lamp pins 2,0. These pins 20' extend longitudinally from the end of the lamp and are parallel to each other, as is well understood in this art. The problem is how to mechanically support and electrically connect these lamp pins 20 with the spring contact members 15 of the lampholder.

The base 10 is a part that is molded of insulating material. The cover 11 is also of insulated material but it is stamped from sheet stock and is mounted flush within the open front wall of the base. It will. be noted that the entrance slot 17 is formed by the converging walls 21 that merge into, the parallel walls 22. 'A' cor-date opening Z3is formed in the cover 11 and it is joined-at its p x i h he entr s ot- 710 he se. j This view. of the lampholder of cordate opening gs, is divided intQ t q arc ats sroett v .4 a 3 24 by a boss 25v that is integrally formed with the back wall of the base and is centrally or concentrically disposed within the opening 23. The boss 25 is generally cylindrical in shape except that it has a pointed top sur face or apex 26 that is directed toward the entrance slot 17, thus giving it the general appearance, as is clearly seen in Figure 1, of a heart-shaped abutment.

The spring contact members 15 of the lampholder are of thin strip material and are braced within the recess of member 10 of the lampholder at their end portion by suitable abutment means. More particularly, the end portions of each contact member, for example, may be fitted into projecting notches or slots (not shown) which are formed integral to the recessed base member 10. The central portion of each contact is folded flatwise into a V-shape as at 30. This location 30 represents a seat in which the pin 20 will rest when the lamp is properly supported in the lampholder, as is best seen in Figure 1. These pin seats 30 are located on a horizontal line that is drawn through the center of the boss 25 and normally lie inside of cordate opening 23. Accordingly, these seats are located in the grooves 24 of the lampholder where the grooves are separated the most. Notice that the innermost ends of the grooves converge inwardly a slight amount. This is important in the exercise of the present invention.

The operating principle of this invention can be best understood by studying the sequential views of Figures 4, and 6. Looking first at Figure 4, the lower pin 20 is engaged in the pin seat 30 of its spring contact 15 while the other pin is disposed within the entrance slot 17 between the parallel walls 22. Clearly, it is not possible to turn the lamp and move the uppermost pin 20 into its groove 24. First, the lamp must be shifted down so that the lower pin 20 will move to the innermost end of its groove 24 against the action of the spring contact 15. Looking at Figure 5, it is apparent that the upper lamp pin 20 has moved out of the slot 17 and into the groove 24. Once the pins have reached the position of Figure 5, the lamp is then turned about its longitudinal axis until the pins slide into the pin seats 30 of the contact members 15 as depicted in Figure 1.

.If vibration causes one of the pins to slip out of engagement with its contact member 15,. the pin that has been released may not slide freely out of its groove 24 and into the slot 17. This is true because there is interference provided by the outer curvature of the groove in the area adjacent the entrance slot. This interference is identified as 31 in Figure 5. The released pin 20 will move toward the'slot 17 but will not enter the slot until the opposite pin is shifted against its contact member 15 and into the innermost end of its groove 24. If the released pin finally enters the slot 17, the lamp is still partially supported within thelampholder by the opposite pin which is held in a semi-locked position as depicted in Figure 6. Here there is a cooperation between the spring force of the contact 15 and the rounded surface ofv the boss 25. This configuration confines the lower pin and is capable of supporting the weightof the lamp against gravity forces. Hence, if one spring contact member were to fail and release its complementary lamp pin, the remaining contact spring would serve to hold both pins in the lampholder until the released pin entered the slot 17. Then the spring contact would hold its lamp pin in a semi-locked position. 7

Having described above my invention of a novel holding arrangement for the contact pins of a bi-pin fluorescent lamp, it will be readily apparent to those skilled in this" art that I have devised a more positive latching ar- 'rangement with the aid of two arcuate grooves that are combined with the spring contact members for both mechanically and electrically connecting the contacts to the lamp pins. While I have chosen to illustrate my invention in a lampholder having a removable front cover that cooperates'in forming the arcuate grooves, it should be readily understood that the grooves could be formed entirely by the molded base. and the cover merely attached to the back surface of the lampholder. In any event, the converging nature of the innermost ends of the grooves is of primary importance as well as the relation of the interference portions of the grooves so that a released pin will not move freely from a groove into the slot without affecting the position of the other pin.

Modifications of this invention will occur to those skilled in this art and it is to be understood, therefore,

that this invention is not limited to the particular em bodirnents disclosed but that it is intended to cover all modifications within the true spirit and scope of this invention as claimed.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A bi-pin fluorescent lampholder comprising a hollow housing that supports a pair of spring contact blades in edgewise fashion with respect to the back wall of the housing, the contact blades having portions which are syrrmietrically arranged within an opening in the front face of said housing, the opening comprising a pair of arcuate grooves, the grooves being connected together adjacent the top portion of the housing and communicating with an entrance slot that is open in both the front cam the seated pin to a semi-locked position, whereby said loosened pin may not be moved into the entrance.

slot until the other pin is shifted out of its seat and toward the innermost 'end of its groove to a semi-locked position, and when manual pressure is released from the lamp, the pin that is at the lower end of the groove will be in a semi-locked position to thereby hold the lamp from dropping out of the lampholder due to its own weight.

the widest portion of the abutment and spaced from said.

2. A bi-pin fluorescent lampholder comprising a hol low housing with an entrance slot in the top and front walls thereof, and a heart-shaped opening in the frontwall with an apex that merges into said slot and a base edge spaced therefrom, a central heart-shaped abutmentl within the housing that is concentrically located with respect to said opening to thereby form a pair of arcuate grooves that join each other at said entrance slot and converge toward each other at their opposite ends, said opposite ends separated by said abutment, and a pair ofspring contact members positioned within said housing, each said member having a V-shaped formation facing inwardly toward the widest portion of said abutment, the.

base edge of said opening overlying said abutment below formations, curved edge means formed in said opening adjacent the entrance slot so that one pin of a seated bi-pin lamp must move below the widest portion of the abutment toward a semi-locked position before the other pin may pass a point in the groove where the groove merges with the slot, whereby after the lamp is properly seated in the lampholder and one pin thereof is accidentally dislodged from its contact, movement of the dis-'- lodged pin into the slot forces the remaining pin into a semi-locked position below the widest portion of the abutment.

3. A bi-pin fluorescent lampholder comprising a hollow housing with an entrance slot in the top and front walls thereof, a pair of arcuate grooves formed in said housing and merging together at the entrance slot, said grooves being curved outwardly from the slot and having spaced opposite ends which converge toward each other,"

a pair of spring contact members arranged within said housing, each said contact member having a pin seat that is in the same plane as the widest spacing of the grooves from each other and is positioned within one of said grooves, the bottom end of each of said grooves being spaced downwardly from an associated pin seat, and camming means adjacent said entrance slot so that a loosened lamp pin is engaged thereby for forcing any seated pin into a semi-locked position at the bottom end of its adjacent groove as said loosened pin passes from its associated groove into the entrance slot, whereby said semi-locked pin at the bottom end of the groove is capable of holding the lamp from falling due to its own weight.

4. A bi-pin fluorescent lampholder comprising a hollow housing with an entrance slot in the top and front walls thereof, and a generally heart-shaped opening in the front wall with an apex that merges into said slot and a base end spaced therefrom, a central heart-shaped abutment within the housing that is concentrically locatcd with respect to said opening to thereby form a pair of arcuate grooves that join each other at said entrance slot and converge toward each other at their opposite ends, said opposite ends separated by said abutment, and a pair of spring contact members positioned within said housing, each said member having aV-shaped formation opening inwardly toward the widest portion of said abutment and exposed by one of said grooves, the base end of said opening positioned below the widest portion of the abutment and spaced from the formations, each groove having an outer side edge, the outer side edge of each groove having a curved portion adjacent the entrance slot spaced from the V-shaped formation exposed by the other groove a distance less than the distance between the lamp pins, thereby to cam one pin of the lamp into a semi-locking position below the widest portion of the abutment by engagement of a loosened pin with the said curved outer edge of said groove upon dislodging of any pin from its contact.

Chirelstein Aug. 4, 1942 Rosen Sept. 11, 1951 

